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My 2001 Raleigh R300 Tourer had a 1" Tange headset that went bad "brunnelling". I bought a 1" threaded nashbar headset with sealed cartridges (I will assume it is ISO). The cups pressed right in to the head tube with no problems, but I fought for a good 20-30 minutes trying to get the crown race on the fork with PVC pipe and have now concluded that it is a JIS 27.0 width. I think I ruined the new crown race. I put the old crown race back on (with the pvc pipe) and 2 good hits with the hammer, so I have concluded that the new race is 26.4 ISO.

(1) I assumed from reading the forums that the JIS was an old standard going back to the 80s and that everything since the mid-90s is ISO.

(2) Can I use my old race with the new sealed cartridge ? The sealed cartridge fits on the race and feels fine. Since the ball bearings are sealed and won't come in direct contact with the race, I think it will work.

My 2001 Raleigh R300 Tourer had a 1" Tange headset that went bad "brunnelling". I bought a 1" threaded nashbar headset with sealed cartridges (I will assume it is ISO). The cups pressed right in to the head tube with no problems, but I fought for a good 20-30 minutes trying to get the crown race on the fork with PVC pipe and have now concluded that it is a JIS 27.0 width. I think I ruined the new crown race. I put the old crown race back on (with the pvc pipe) and 2 good hits with the hammer, so I have concluded that the new race is 26.4 ISO.

Most likely.
ISO frame races (30.2 mm) often fit just fine in J.I.S. head tubes (30.0 mm) partly because the difference is so small, and partly because head tubes are relatively "stretchy."

The crown race is much fussier, partly because of the greater difference in diameter, and partly because the crown race is brittle, usually hardened steel, with little "give."

Quote:

Originally Posted by marnan

(1) I assumed from reading the forums that the JIS was an old standard going back to the 80s and that everything since the mid-90s is ISO.

Nope. I'm not surprised that a relatively low-end model like that would be J.I.S.

A good bike shop would be able to mill the seat on the fork crown to ISO size.

Quote:

Originally Posted by marnan

(2) Can I use my old race with the new sealed cartridge ? The sealed cartridge fits on the race and feels fine. Since the ball bearings are sealed and won't come in direct contact with the race, I think it will work.

Never heard of anyone doing that, but if it looks like a good fit, it's probably fine.

Thanks Sheldon,
I appreciate you disecting my questions and providing all the answers. I tightened up the headset with the old crown race and it is smooth as butter, but I should know more after tommorrow's commute. The old crown race is brunelled, but it doesn't matter since the sealed cartridge sits on the race. This was quite a learning experience for me. Also, thanks for your website and information. I have been visiting your website regularly for the last 5-6 years when I started bike commuting to work. I started with the R300 tourer, but the only original parts left are the frame, fork, Avid 4 brakes, and brake cables. Replacing the brakes is next and then someday a steel frame, probably a Surly LHT.